1. Field of the Invention
The present invention relates to a heat sink including a heat dissipating fin and a method for fixing the heat dissipating fin to the heat sink main body. A heat sink including a heat dissipating fin according to the present invention may be utilized not only for heat dissipating and cooling of a heat generating electronic component or the like used in an electronic device but also for heat dissipating and cooling of articles in any field which require heat dissipation.
2. Description of the Related Art
A semiconductor chip or the like used in various electronic devices such as a personal computer, a game console, an audio system or the like has been made smaller in size, and larger in integration density to remarkably improve processing speed, and therewith heat generating density thereof becomes much larger.
Various corrugated fins such as those comprising sequentially connected elongate U shaped parts (hereinafter referred to as xe2x80x9celongated folded finxe2x80x9d) are widely used as a means for dissipating the heat generated by a semiconductor chip or the like having large heat generating density which is mounted in such electronic devices as a personal computer, a game console, an audio system or the like. Although the elongated folded fin is light in weight and has a limited enveloped volume, the heat dissipating area thereof can be made wider.
The heat generated by a heat source is transferred to a heat transfer plate, block or the like, and then the heat thus transferred is dissipated through the elongated folded fin attached to the heat transfer plate, block or the like. The elongated folded fin is joined to the heat transfer plate, block or the like by brazing or soldering. Alternatively, the elongated folded fin is fixed to the heat transfer plate, block or the like by caulking or screwing. Furthermore, the elongated folded fin is adhered by an adhesive agent, a double-sided adhesive tape or the like.
However, the above-mentioned conventional method for attaching the elongated folded fin to the heat transfer plate, block or the like has the following problems. Namely, the method of joining the elongated folded fin to the heat transfer plate, block or the like by brazing or soldering, as well as the method of adhering the heat transfer plate, block or the like by the adhesive agent have a problem of its high processing cost. Additionally, the method of joining the elongated folded fin to the heat transfer plate, block or the like by brazing or soldering has a problem that the fin is softened and the strength thereof is lowered by the heat in the joining process.
The method of fixing the elongated folded fin to the heat transfer plate, block or the like by caulking or screwing, as well as the method of adhering the elongated folded fin to the heat transfer plate, block or the like by the double-sided adhesive tape have a problem in which the heat transfer resistance (i. e, contact heat resistance) between the elongated folded fin and the heat transfer plate, block or the like becomes large.
Furthermore, the method of adhering the elongated folded fin to the heat transfer plate, block or the like by an adhesive agent has a problem in which the products thus processed do not have uniform heat transfer resistance, thus having a different quality in heat transfer resistance.
An object of the present invention is therefore to provide a heat sink including a heat dissipating fin which is inexpensive in processing cost, uniform in heat transfer resistance and excellent in heat transfer efficiency without degrading the strength of the fin, and a method for fixing the heat dissipating fin to the heat sink main body.
The inventors have been studying hard to solve the above-mentioned problems in the conventional art. As a result, the following findings are obtained.
More specifically, it has been found that it is possible to provide a heat sink including a heat dissipating fin, being inexpensive in processing cost, uniform in heat transfer resistance and excellent in heat transfer efficiency without degrading the strength of the fin, by firstly preparing a heat dissipating fin in a shape of a folded fin comprising mountain-shaped portions, a base member and a fitting member, then forming in the base member square slits having the size and number corresponding to the width, depth, mountain pitch, number of mountains of the heat dissipating fin, and holes for fixing the heat dissipating fin, then making on the fitting member projecting portions corresponding to the holes, then inserting the heat dissipating fins into the slits, fitting the projecting portions into the holes, pressing the heat dissipating fin between the base member and the fitting member, and caulking the heads of the fitted projecting portions, thereby fixing the heat dissipating fin.
Furthermore, it has been found that the same effect as described above can be also obtained by providing in a fitting member holes for fixing a heat dissipating fin and providing in a base member projecting portions corresponding to the holes.
In addition, it has been found that it is possible to more effectively fix a heat dissipating fin between a base member and a fitting member by providing a curved portion in a part of the base member and pressing the heat dissipating fin by the curved portion.
The present invention has been made on the basis of the information obtained as described above.
The first embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, comprising:
(1) a heat dissipating fin having a plurality of mountain-shaped portions and base portions supporting said mountain-shaped portions;
(2) a base member having a plurality of slits into which said mountain-shaped portions of said heat dissipating fin are to be inserted and a plurality of holes for fixing said heat dissipating fin; and
(3) a fitting member, provided with a plurality of projecting portions corresponding to said plurality of holes of said base member, for fixing said heat dissipating fin between said base member and the fitting member itself.
The second embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, comprising:
(1) a heat dissipating fin having a plurality of mountain-shaped portions and base portions supporting said mountain-shaped portions;
(2) a base member having a plurality of slits into which said mountain-shaped portions of said heat dissipating fin are to be inserted and a plurality of projecting portions for fixing said heat dissipating fin; and
(3) a fitting member, provided with a plurality of holes corresponding to said plurality of projecting portions of said base member, for fixing said heat dissipating fin between said base member and the fitting member itself.
The third embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, wherein:
said mountain-shaped portions of said heat dissipating fin are inserted into said slits of said base member, said base portions of said heat dissipating fin are put between said base member and said fitting member, said projecting portions are fitted into said holes, and said projecting portions are caulked, thereby said heat dissipating fin is fixed between said base member and said fitting member.
The fourth embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, wherein:
at least a part of regions positioned between said plurality of slits of said base member, said regions being to come into contact with said base portions of said heat dissipating fin, forms a curved portion by being drawn down toward said fitting member in such manner that said heat dissipating fin is fixed between said base member and said fitting member by means of an elastic action of said curved portion.
The fifth embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, wherein:
when said heat dissipating fin is fixed between said base member and said fitting member in such manner that regions of said base member which come into contact with said base portions of said heat dissipating fin are drawn up by a distance corresponding to a thickness of said base member toward said heat dissipating fin, a lower face of the base portions of said heat dissipating fin and a lower face of said base member are positioned nearly in a same plane.
The sixth embodiment of a heat sink of the present invention is a heat sink including a heat dissipating fin, wherein:
a heat pipe is thermally connected to said fitting member in such manner that heat transferred by said heat pipe is dissipated through said fitting member and said heat dissipating fin.
The first embodiment of a method of the invention is a method for fixing a heat dissipating fin, comprising the steps of:
(1) preparing a heat dissipating fin comprising a plurality of mountain-shaped portions and base portions supporting said mountain-shaped portions;
(2) preparing a base member having a plurality of slits into which said plurality of mountain-shaped portions are to be inserted and a plurality of holes;
(3) preparing a fitting member provided with a plurality of projecting portions corresponding to said plurality of holes of said base member;
(4) inserting said mountain-shaped portions of said heat dissipating fin into said slits of said base member, putting said base portion of said heat dissipating fin between said base member and said fitting member, and fitting said projecting portions into said holes; and
(5) caulking said projecting portions which are fitted into said holes, thereby fixing said heat dissipating fin between said base member and said fitting member.
The second embodiment of a method of the invention is a method for fixing a heat dissipating fin, comprising the steps of:
(1) preparing a heat dissipating fin comprising a plurality of mountain-shaped portions and base portions supporting said mountain-shaped portions;
(2) preparing a base member having a plurality of slits into which said plurality of mountain-shaped portions are to be inserted and a plurality of projecting portions;
(3) preparing a fitting member provided with a plurality of holes corresponding to said plurality of projecting portions of said base member;
(4) inserting said mountain-shaped portions of said heat dissipating fin into said slits of said base member, putting said base portion of said heat dissipating fin between said base member and said fitting member and fitting said projecting portions into said holes; and
(5) caulking said projecting portions which are fitted into said holes, thereby fixing said heat dissipating fin between said base member and said fitting member.
The third embodiment of a method of the invention is a method for fixing a heat dissipating fin, further comprising the steps of:
in preparation of said base member, forming a curved portion by drawing down at least a part of regions positioned between said plurality of slits of said base member, said regions being to come into contact with said base portions of said heat dissipating fin, toward said fitting member in such manner that said heat dissipating fin is fixed between said base member and said fitting member by means of an elastic action of said curved portion.
The fourth embodiment of a method of the invention is a method for fixing a heat dissipating fin, further comprising the steps of:
in preparation of said base member, when fixing said heat dissipating fin between said base member and said fitting member in such manner that regions of said base member which come into contact with said base portions of said heat dissipating fin are drawn up by a distance corresponding to a thickness of said base member toward said heat dissipating fin, a lower face of the base portion of said heat dissipating fin and a lower face of said base member are prepared so as to be positioned nearly in the same plane.
The fifth embodiment of a method of the invention is a method for fixing a heat dissipating fin, further comprising the step of providing a heat pipe so as to be thermally connected to said fitting member.